Organic Molecules
Title: Benedict ’s test for Reducing Sugars
Testable Question: Are all carbohydrates reducing sugars?
Hypothesis: If the carbohydrate contains available ketone or aldehyde molecules then they are reducing sugars.
Variables:
a. Independent: Function groups react w/ reagent
b. Dependent: Color change (red, orange, yellow)
Control: Water
Materials:
- 4 mL of each solution (Water, Starch, Glucose, Maltose, Sucrose, Onion Juice, Potato slice, Milk)
- 8 test tubes
- 8 pipetes
- Benedicts regagent
- 150 mL of water
- Beaker
- 1 pair of tongs
- Test tube rack
- Hot plate
- Dropper
- Timer
Procedure:
1. Set up a row of eight test tubes. Use a marker to number them 1 through 8.
2. To each test tube, add 4 mL of the solutions listed above, matching each number to the number on the tube.
3. Add one dropperful (2mL) of Benedict’s reagent to each tube.
4. Mix the reagent and the sample by agitating the solution in each tube from side to side. Record the original color of each tube’s contents in your data table.
5. Heat the test tubes in a boiling water bath for 2 minutes. Record any color changes in the data table you created.
6. Pour the contents of each test tube down the sink and flood with water. Wash out and dry each test tube and ready them for the next exercise.
Title: Lugol’s Test for Starch
Testable Question: Are all carbohydrates polysaccharides?
Hypothesis: If a carbohydrate is a polysaccharide, then it will react with the reagent and change color.
Variables: a) Independent: The type of carbohydrate
b) Dependent: Color change
Control: Water
Materials:
- 4 mL of each solution (Water, Starch, Glucose, Maltose, Sucrose, Onion Juice, Potato slice, Milk)
- 8 test tubes
- 8 pipetes
- Lugol’s regagent
- Test tube rack
- Dropper
Procedure:
1. Prepare your
Testable Question: Are all carbohydrates reducing sugars?
Hypothesis: If the carbohydrate contains available ketone or aldehyde molecules then they are reducing sugars.
Variables:
a. Independent: Function groups react w/ reagent
b. Dependent: Color change (red, orange, yellow)
Control: Water
Materials:
- 4 mL of each solution (Water, Starch, Glucose, Maltose, Sucrose, Onion Juice, Potato slice, Milk)
- 8 test tubes
- 8 pipetes
- Benedicts regagent
- 150 mL of water
- Beaker
- 1 pair of tongs
- Test tube rack
- Hot plate
- Dropper
- Timer
Procedure:
1. Set up a row of eight test tubes. Use a marker to number them 1 through 8.
2. To each test tube, add 4 mL of the solutions listed above, matching each number to the number on the tube.
3. Add one dropperful (2mL) of Benedict’s reagent to each tube.
4. Mix the reagent and the sample by agitating the solution in each tube from side to side. Record the original color of each tube’s contents in your data table.
5. Heat the test tubes in a boiling water bath for 2 minutes. Record any color changes in the data table you created.
6. Pour the contents of each test tube down the sink and flood with water. Wash out and dry each test tube and ready them for the next exercise.
Title: Lugol’s Test for Starch
Testable Question: Are all carbohydrates polysaccharides?
Hypothesis: If a carbohydrate is a polysaccharide, then it will react with the reagent and change color.
Variables: a) Independent: The type of carbohydrate
b) Dependent: Color change
Control: Water
Materials:
- 4 mL of each solution (Water, Starch, Glucose, Maltose, Sucrose, Onion Juice, Potato slice, Milk)
- 8 test tubes
- 8 pipetes
- Lugol’s regagent
- Test tube rack
- Dropper
Procedure:
1. Prepare your